2020 G90 engine knock and power failure

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! It sounds like your Genesis G90 has a serious issue, especially with the engine knock and power loss right after fueling up. A sudden problem like this could point to a fuel delivery issue, which could mess with your injectors and spark plugs. The dealership's estimate for plugs and injectors seems high. Spark plugs themselves usually don't run that high unless they’re charging a hefty premium for labor or OEM parts. It's also worth asking if they've confirmed that all eight injectors are really toast or if it's just a cautious diagnosis. I've also seen engines be really finicky if the fuel grade is incorrect. Check your owner's manual to make sure you're using the right fuel! If the fuel was contaminated, you may need more than just injectors and plugs—like a full fuel system clean. It’s worth seeking a second opinion before committing to the repair. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554.